Voltage-regulator for electric generators.



A H. OLMSTED. VOLTAGE REGULATOR FOR ELECTRIC GENERATORS.

APPLICATION FILED JAN-28,1913.

3 SHEETS-SHEET I .IILuIL TJ L INVENTOR.

WITNESSES 77 /ZQQaA/L/ ATTURNF A. H. OLMSTED. VOLTAGE REGULATOR FOR ELECTRIC GENERATORS. APPLICATION FILED JAN.2B. 1913 1,1 62,506. Patented Nov, 30, 1915.

3 SHEETS-SHEET 2- WITNESSES INVENTOK gym ATTORNEY APPLICATION FILED JAN. 28, I913.

Patented Nov, 30, 191".

3 SHEETS-SHEET 3.

Regulators for Electric one part of the apparatus. elevation and Fi at a side elevation of a HOLLEY OLMSTEID, IEOWDON,

VOLTAGE-REGULATOR FOR ELECTRIC GENESEtATO Specification of Letters Eetent.

Application filed Januaryfifl, 1813. Serial No. Wi he m.

To all 107mm it may concern:

Be it known that I, ALEXANDER HoLLnY OLMSTED, a citizen of the United States of Americag-and a resident of Bowdon, in the county of Chester, England, have invented a new and useful Improvement in Voltage- Generators, of which the following is a specification.

This invention relates to voltage regulators of the kind adapted to vary the excitation of an electric generator or of its exciters, so as to maintain a constant voltage on the generator terminals and is an improvement in or modification of the voltage regulator, described in the specification of application for British Letters Patent No. 28747 of 20th December 1911.

In the regulator described in the above mentioned specification, a resistance in series with the field magnet winding of' the generator or its exciter is arranged to be short circuited through two contacts operated by arelay magnet and a short-circuit around the Inagnetis made and broken by another pair of contacts one of which is carried on a vibrating arm whose rate of oscillation is caused to vary automatically in accordance with variation in voltage of the generator. Said vibrating arm is caused to oscillate by means of an electro-magnet the circuit of which is made and broken by two contacts, one of which is carried on said arm and the other on another arm, the position of which varies in accordance with the voltage of the generator to be controlled.

According to the present invention the contact with which the contact on the vibrating arm co-iiperates is fixed and the construction and arrangement of the regulator are such that the use of a spring for causing these contacts to close when the operating magnet of the vibrating arm is deenergiz'ed is dispensed with. I i

The invention further comprises certain improvements in the construction of the regulator.

In order that the nature of the invention may be clearly understood a voltage regulator embodying the same will now be described with reference to the accompanying drawings in which Figure 1 is a front elevation and Fig. 2 side elevation of a preferred construction of Fig. 3 is a front preferred construction of ancthe' of the apparatus, and Fig. 5 is a diagrammatic view showing the electrical connections of the various devices with the eXciter which excites the field magnets of the machine supplying current to the circuit to be regulated.

Referring now to Figs. 1 and a magnet hereinafter referred to as the main magnet which is energized directly or indirectly from the generator the voltage of which is to be controlled, is provided with a coil 1 and two cores 2, 3. of which the core is mounted on an arm or: lever l pivoted below the magnet the other core bci adjustably supported within "he coil from a Ll t bracket 5 by means or" the S the cores :2 and 3 are provided. with a 'ial cuts 7 to reduce eddy currents therein. pivoted lever -1 supported ring o from a bracket f t adjusted by means oi screw 10 in the ordinary way and it will be. readily seen that if the coil 1 is supplied with current and the voltage at the terminals thereof is maintained constant the ring can be aj justed so that the lever 4- 1 be maintained in equilibrium in any position. 11 is a dash pot carried on a fixed bracket 12 the piston of which is pivotally attached to a Hat spring 15 secured to the lever i. The object of this spring is partially to reduce humming and partly to assist the lever and core 2 to adjust themselves to any position which they are caused to take by variation in the pull of themain magnet. Another magnet iereinafter "termed the vibrator magnet is provided with coil 1- a core 15, a fixed pole 1U and an adjustable pole 17. The armature which cooperates with the adjustable pole piece is indicated at 18 and consists of a thin strip of iron mounted on a lever 19 which in turn is mounted on a shaft 20 being in sulated therefrom by a mica sleeve Elie shaft 520 is arranged to rotate in bearing for'med by the screws '22., 2 5'; in a fixed bracket 2: 1. The arm 19 carries at it ree end a contact preferably formed at. silver which cooperates wfth a similar cont-a mounted on a sprin it 26 V secured bracket 28. Carried to a nxed the lever 19 arm 29 on which s m n J said contact c mounted on; of this lev 24 by sore and of one ed to the to spring being the contacts 30 d 31 Lug.

bracket 24 has its other end connected to the lever and holds said lever lightly against a stop 36 mounted in a bracket 37 attachedpasses through the relay coils 38 and 39 Will to the lever s.

L'leferring new to Figs. 3 and in which show the relay magnet which operates the contacts for short-circuiting the resistance in series with the generator or its exciter 3S, are two coils connected in series and mounted respectively on the cores i and all the lower ends of which are connected. by an iron piece l2 which is carried on a braclre secured to a suit-aide base 4 The ature oi the magnet is indicated l5 and is" carried by an arm l6 pivoted at .5 Saidarinature carries an adjustable Contact -28 prefe ably of silver which cooperates with a similar contacti) carried by an arm mounted on a fixed bracket 51 a spring 52 tcniiling to maintain the two r -3 in connection. e ma nets, brackets and other. fixed s of apparatus above described are i. "123 bc a panel of a switchboard for .Jcaied at in 2 and 3. i to diagram Fig. 5, cle erical connections of YfillOllS parts, the coil. 1 of the main magnet is connected by wires"i"2, 73 across two of the terminals of a 8-phase alternator 68 supplying mains 69, 70, 71, the voltage of which is to be regulated, the. field windin; 71%. of the alternator 68 bein'g connected across the brushes of the e'nciter Transformers or suitable resistances may, or" course, be interposed betw en the magnet and the circuit if necessary. The coil is: of the 'iliralor iagn t is connected by a wire. 5 to one pole of a storage battery 54 be other pole of which is connected through wire So lever lib contacts 25am 2%, sprung 27 and wire so to the other tern'iina'l of the coil ii. resistance 57 serves to minimize ii m :hich occurs on breaking the coun 2o: een the contacts '25, 2b. The coils 38 55.? of the relay magnet are enernixed 2n the 'cr-icitcr the armature of which indicated at 58, the current passing; by a wire through the battery 54, wire Sin contacts 30 and 31, wire (36, relay coils 38, 3!), wire (El and resistance 62 to the negative terminal of the exciter. idesistancc 6 :5 connected between the wires and serves to minimize the spark which occurs on braking the connection between The field magnet coil of the excitcr is indicated at M and in its licld circuit is arranged a rcsisiance, one portion 35 of which has its terminals connected to iho relay contacts 48 and it? so as to he suart-circuitod when the relay coils 2 .8 and Eli) are not energized The operation of the regulator is s: tially as 'l'ollowsk ii he batltezy 54. w;

conveniently niouni'ied on the same base increases i inually receive a charging current from the exciter armature 58 through the resistance 66 and the current from the exciter which cooperating contacts 25 and 26 in coni L1I1C-- tion with the battery l will operate to cause the arm 19 to vibrate with a regular frequency after the manner of an electric tremblingiell and thus cause contact 30 to vibrate with a perfectly definite travel and frequency of vibration. the weight of lever and the force of'the spring 35 being so small. compared with'the mass of the lever 19 that the fact of the contacts 30 and 31 being in or out of engagement will not :iliect the vibration of the lever 15). The circuit of the relay coils 21d 39 is made and broken by the contacts 30 and 31 and the length of time per vibration ofthe' lever 19 that these contacts remain in engagelnez'u will be determined the position of the stop 36 which is carried on the lever l. The position of this lever anc of the stop which it carries will vary in accordance with variations in the voltage applied to the terminals of the main nia net coil 1, and consequently the periods of time during which the relay coils 38 and 39 are energized and the corresponding periods of time during. which the resistance in the field circuit of the exciter is not short-circuited will be varied in a similar manner.

it will be observed that in the upper extreme position of the stop 36 which it takes whenthe voltage applied to the main magnet coil 1 exceeds a certain predetermined limit the contacts 30 and 31 remain permanently in engagement, whereas in the eX- treine lower position of the stop 36 which occurs when the voltage applied to the main magnet coil. l below another predetermined limit tl contact 31 will not be engaged by the contact 30. in the first case the resistance (35 will always be included in the exciter field circuit whereas in the sec- I magnet for vibrating said arm at a substantially constant irexnicncy, a pair of auxiliary contact members controlling the circuit of the clectroiuagnet one of w ch menr circuit being made and broken and suit I hers is carried by the said arm, a second arm upon which the other main contact member is mounted, means normally tending to cause the'main contact members to engage, a third arm for varying the position of the second arm, and means for governing the position of the third arm in accordance with variations of the quantity regulated.

An,electrical regulator comprising cooperating main contact members, an arm carrying one of said members, an electro magnet for Vibrating said arm at a substantially constant frequency, a pair of auxiliary contact members controlling the circuit of the said electromagnet one of which members is carried by the said arm, a second arm upon which the other main contact member is mounted, means normally tending to cause the main contact members to engage, a third arm for Varying the position of the second arm, means for governing the position of t. e third arm in accordance with variations of the quantity regulated, and means resiliently connected to, and retarding the operation of, the third arm.

2%, in electrical regulator comprising cobrating said members into and out of en- 'agement, means for controlling the position ofone of said members in accordance with the value of the regulated :quantity, and means resiliently connected to, and retarding the operation of, the latter means.

In testimony whereof, I have hereunto subscribed my name this tenth day of Januarv 1913.

ALEXANDER HOLLEY OLMS'IED.

perating contact members, means for Vi 

